Percutaneously implantable paddle-type lead and methods and devices for deployment

ABSTRACT

A percutaneously implantable paddle lead includes an elongated lead body having a proximal portion and a distal portion; a plurality of terminals disposed on the proximal portion of the lead; a flexible paddle body coupled to the distal portion of the lead; and a plurality of electrodes disposed in the paddle body and electrically coupled to the terminals on the proximal portion of the lead. The percutaneously implantable paddle lead also includes a bonding material in contact with the paddle body and holding the paddle body in a compacted form prior to, and during, insertion into a percutaneous implantation tool. The bonding material is configured and arranged to release the paddle body during or soon after implantation into a patient so that the paddle body can deploy into its paddle-like form. Alternatively, at least one current-degradable fastener can be used instead of the binding material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/299,725 filed Nov. 18, 2011, which issued as U.S. Pat. No. 9,265,934on Feb. 23, 2016, which claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application Ser. No. 61/419,372 filed on Dec. 3,2010, both of which are incorporated herein by reference.

FIELD

The present invention is directed to the area of devices and methods forstimulation of tissue using an array of electrode contacts, as well asmethods of making and using the devices. In addition, the presentinvention is directed to the area of devices and methods for stimulationof tissue using a percutaneously deliverable paddle lead.

BACKGROUND

Stimulation systems have been developed to provide therapy for a varietyof disorders, as well as for other treatments. For example, stimulationsystems can be used in neurological therapy by stimulating nerves ormuscles, for urinary urge incontinence by stimulating nerve fibersproximal to the pudendal nerves of the pelvic floor, for erectile andother sexual dysfunctions by stimulating the cavernous nerve(s), forreduction of pressure sores or venous stasis, etc. Spinal cordstimulation is a well accepted clinical method for reducing pain incertain populations of patients.

Implantable stimulation devices have been developed to provide therapyfor a variety of treatments. For example, implantable stimulationdevices can be used to stimulate nerves, such as the spinal cord,muscles, or other tissue. An implantable stimulation device typicallyincludes an implanted control module (with a pulse generator), a lead,and an array of stimulator electrode contacts. The stimulator electrodecontacts are implanted in contact with or near the nerves, muscles, orother tissue to be stimulated. The pulse generator in the control modulegenerates electrical pulses that are delivered by the electrode contactsto body tissue. As an example, electrical pulses can be provided to thedorsal column fibers within the spinal cord to provide spinal cordstimulation.

The stimulation electrode contacts may be disposed on a percutaneousspinal cord stimulation lead or a paddle-type lead. Percutaneous spinalcord stimulation leads are at risk of migration once implanted. As aresult of lead migration, electrode contacts may be in a nontherapeuticlocation or may have a suboptimal orientation relative to anotherimplanted lead. In contrast, paddle-type leads mitigate these problemsassociated with percutaneous leads due to their larger relative size andfixed electrode orientation. Unfortunately, their size requires a moreinvasive surgical implantation procedure than that used for percutaneousleads. Thus, implantation of conventional paddle-type leads may includeinvasive procedures such as a laminotomy or laminectomy. This invasivesurgery typically requires surgical training and can be time consumingand costly.

BRIEF SUMMARY

One embodiment is a percutaneously implantable paddle lead that includesan elongated lead body having a proximal portion and a distal portion; aplurality of terminals disposed on the proximal portion of the lead; aflexible paddle body coupled to the distal portion of the lead; and aplurality of electrodes disposed in the paddle body and electricallycoupled to the terminals on the proximal portion of the lead. Thepercutaneously implantable paddle lead also includes a bonding materialin contact with the paddle body and holding the paddle body in acompacted form prior to, and during, insertion into a percutaneousimplantation tool. The bonding material is configured and arranged torelease the paddle body during or soon after implantation into a patientso that the paddle body can deploy into its paddle-like form.

Another embodiment is a percutaneously implantable paddle lead thatincludes an elongated lead body having a proximal portion and a distalportion; a plurality of terminals disposed on the proximal portion ofthe lead; a flexible paddle body coupled to the distal portion of thelead; and a plurality of electrodes disposed in the paddle body andelectrically coupled to the terminals on the proximal portion of thelead. The percutaneously implantable paddle lead further includes atleast one current-degradable fastener in contact with the paddle bodyand holding the paddle body in a compacted form prior to, and during,insertion into a percutaneous implantation tool. The current-degradablefastener is configured and arranged to release the paddle body uponapplication of at least a threshold current to allow the paddle body todeploy into its paddle-like form.

Yet another embodiment is a method of percutaneously implanting animplantable paddle lead. The method includes inserting at least a paddlebody of the paddle lead into a percutaneous insertion tool. The paddlebody is compacted into a form that is percutaneously implantable andincludes a degradable binding material in contact with the paddle bodyand holding the paddle body in its compacted form. The method furtherincludes implanting the paddle body near tissue to be stimulated in abody of a patient; and degrading the binding material to release thepaddle body from its compacted form and allow it to deploy to itspaddle-like form.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings. In the drawings,like reference numerals refer to like parts throughout the variousfigures unless otherwise specified.

For a better understanding of the present invention, reference will bemade to the following Detailed Description, which is to be read inassociation with the accompanying drawings, wherein:

FIG. 1 is a schematic view of one embodiment of an electricalstimulation system that includes a paddle body coupled to a controlmodule via lead bodies, according to the invention;

FIG. 2A is a schematic side view of one embodiment of a plurality ofconnector assemblies disposed in the control module of FIG. 1, theconnector assemblies configured and arranged to receive the proximalportions of the lead bodies of FIG. 1, according to the invention;

FIG. 2B is a schematic side view of one embodiment of a proximal portionof a lead body and a lead extension coupled to a control module, thelead extension configured and arranged to couple the proximal portion ofthe lead body to the control module, according to the invention;

FIG. 2C is a schematic side view of one embodiment of a connectorassembly disposed in the control module of FIG. 2B, the connectorassembly configured and arranged to receive the lead extension of FIG.2B, according to the invention;

FIG. 3A is a schematic cross-sectional view of one embodiment of apaddle body of a lead within bonding material, according to theinvention;

FIG. 3B is a schematic cross-sectional view the paddle body of the leadof FIG. 3A during deployment, according to the invention;

FIG. 3C is a schematic cross-sectional view the paddle body of the leadof FIG. 3A after deployment, according to the invention;

FIG. 4A is a schematic cross-sectional view of one embodiment of apaddle body of a lead having a fastener, according to the invention;

FIG. 4B is a schematic top view the paddle body of the lead of FIG. 4A,according to the invention;

FIG. 4C is a schematic cross-sectional view the paddle body of the leadof FIG. 4A during deployment, according to the invention;

FIG. 4D is a schematic top view the paddle body of the lead of FIG. 4Aduring deployment, according to the invention;

FIG. 4E is a schematic cross-sectional view the paddle body of the leadof FIG. 4A after deployment, according to the invention;

FIG. 4F is a schematic top view the paddle body of the lead of FIG. 4Aafter deployment, according to the invention;

FIG. 5A is a schematic cross-sectional view of one embodiment of apaddle body of a lead having a current-sensitive binder, according tothe invention;

FIG. 5B is a schematic cross-sectional view the paddle body of the leadof FIG. 5A during deployment, according to the invention;

FIG. 5C is a schematic cross-sectional view the paddle body of the leadof FIG. 5A after deployment, according to the invention;

FIG. 6A is a schematic perspective view of one embodiment of a leadhaving current-degradable fasteners, according to the invention;

FIG. 6B is a schematic perspective view of another embodiment of a leadhaving current-degradable fasteners, according to the invention;

FIG. 6C is a schematic perspective view of a third embodiment of a leadhaving current-degradable fasteners, according to the invention;

FIG. 7A is a schematic perspective view of one embodiment of a leadhaving an explant support and an explant tool before explant, accordingto the invention;

FIG. 7B is a schematic perspective view of the lead and explant tool ofFIG. 7A during explant, according to the invention; and

FIG. 8 is a schematic perspective overview of one embodiment ofcomponents of an electrical stimulation system, including an electronicsubassembly disposed within a control module, according to theinvention.

DETAILED DESCRIPTION

The present invention is directed to the area of devices and methods forstimulation of tissue using an array of electrode contacts, as well asmethods of making and using the devices. In addition, the presentinvention is directed to the area of devices and methods for stimulationof tissue using a percutaneously deliverable paddle lead.

The paddle leads described herein may be percutaneously implantable.This may obviate the need for performing an invasive procedure such as alaminotomy or laminectomy for implantation of the paddle lead. Suitableimplantable electrical stimulation systems include, but are not limitedto, an electrode lead (“lead”) with one or more electrode contactsdisposed on a distal end of the lead and one or more terminals disposedon one or more proximal ends of the lead. Examples of electricalstimulation systems with leads are found in, for example, U.S. Pat. Nos.6,181,969; 6,516,227; 6,609,029; 6,609,032; and 6,741,892; 7,244,150;7,672,734 7,761,165; 7,949,395; 7,974,706; and U.S. Patent ApplicationsPublication Nos. 2005/0165465, 2007/0150036; 2007/0219595; and2008/0071320, all of which are incorporated by reference.

FIG. 1 illustrates schematically one embodiment of an electricalstimulation system 100. The electrical stimulation system includes acontrol module (e.g., a stimulator or pulse generator) 102, a paddlebody 104, and one or more lead bodies 106 coupling the control module102 to the paddle body 104. The paddle body 104 and the one or more leadbodies 106 form a lead. The paddle body 104 typically includes aplurality of electrode contacts 134 that form an array of electrodecontacts 133. The control module 102 typically includes an electronicsubassembly 110 and an optional power source 120 disposed in a sealedhousing 114. In FIG. 1, two lead bodies 106 are shown coupled to thecontrol module 102.

The control module 102 typically includes one or more connectorassemblies 144 into which the proximal end of the one or more leadbodies 106 can be plugged to make an electrical connection via connectorcontacts (e.g., 216 in FIG. 2A). The connector contacts are coupled tothe electronic subassembly 110 and the terminals are coupled to theelectrode contacts 134. In FIG. 1, two connector assemblies 144 areshown.

The one or more connector assemblies 144 may be disposed in a header150. The header 150 provides a protective covering over the one or moreconnector assemblies 144. The header 150 may be formed using anysuitable process including, for example, casting, molding (includinginjection molding), and the like. In addition, one or more leadextensions 224 (see FIG. 2B) can be disposed between the one or morelead bodies 106 and the control module 102 to extend the distancebetween the one or more lead bodies 106 and the control module 102.

The electrical stimulation system or components of the electricalstimulation system, including one or more of the lead bodies 106, thepaddle body 104, and the control module 102, are typically implantedinto the body of a patient. The electrical stimulation system can beused for a variety of applications including, but not limited to, spinalcord stimulation, brain stimulation, neural stimulation, muscleactivation via stimulation of nerves innervating muscle, and the like.

The electrode contacts 134 can be formed using any conductive,biocompatible material. Examples of suitable materials include metals,alloys, conductive polymers, conductive carbon, and the like, as well ascombinations thereof. In at least some embodiments, one or more of theelectrode contacts 134 are formed from one or more of: platinum,platinum iridium, palladium, palladium rhodium, titanium, or titaniumnitride.

The number of electrode contacts 134 in the array of electrode contacts133 may vary. For example, there can be four, five, six, seven, eight,nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, or moreelectrode contacts 134. As will be recognized, other numbers ofelectrode contacts 134 may also be used. In FIG. 1, sixteen electrodecontacts 134 are shown. The electrode contacts 134 can be formed in anysuitable shape including, for example, round, oval, triangular,rectangular, pentagonal, hexagonal, heptagonal, octagonal, or the like.

The electrode contacts of the paddle body 104 or one or more lead bodies106 are typically disposed in, or separated by, a non-conductive,biocompatible material including, for example, silicone, polyurethane,and the like or combinations thereof. The paddle body 104 and one ormore lead bodies 106 may be formed in the desired shape by any processincluding, for example, molding (including injection molding), casting,and the like. Electrode contacts and connecting wires can be disposedonto or within a paddle body either prior to or subsequent to a moldingor casting process. The non-conductive material typically extends fromthe distal end of the lead to the proximal end of each of the one ormore lead bodies 106. The non-conductive, biocompatible material of thepaddle body 104 and the one or more lead bodies 106 may be the same ordifferent. The paddle body 104 and the one or more lead bodies 106 maybe a unitary structure or can be formed as two separate structures thatare permanently or detachably coupled together.

Terminals (e.g., 210 in FIG. 2A) are typically disposed at the proximalend of the one or more lead bodies 106 for connection to correspondingconductive contacts (e.g., 216 in FIG. 2A) in connector assembliesdisposed on, for example, the control module 102 (or to other devices,such as conductive contacts on a lead extension, an operating roomcable, a lead splitter, a lead adaptor, or the like). Conductive wires(not shown) extend from the terminals to the electrode contacts 134.Typically, one or more electrode contacts 134 are electrically coupledto a terminal (e.g., 210 in FIG. 2A). In some embodiments, each terminal(e.g., 210 in FIG. 2A) is only coupled to one electrode contact 134.

The conductive wires may be embedded in the non-conductive material ofthe lead or can be disposed in one or more lumens (not shown) extendingalong the lead. In some embodiments, there is an individual lumen foreach conductive wire. In other embodiments, two or more conductive wiresmay extend through a lumen. There may also be one or more lumens (notshown) that open at, or near, the proximal end of the lead, for example,for inserting a stylet rod to facilitate placement of the lead within abody of a patient. Additionally, there may also be one or more lumens(not shown) that open at, or near, the distal end of the lead, forexample, for infusion of drugs or medication into the site ofimplantation of the paddle body 104. The one or more lumens may,optionally, be flushed continually, or on a regular basis, with saline,epidural fluid, or the like. The one or more lumens can be permanentlyor removably sealable at the distal end.

As discussed above, the one or more lead bodies 106 may be coupled tothe one or more connector assemblies 144 disposed on the control module102. The control module 102 can include any suitable number of connectorassemblies 144 including, for example, two three, four, five, six,seven, eight, or more connector assemblies 144. It will be understoodthat other numbers of connector assemblies 144 may be used instead. InFIG. 1, each of the two lead bodies 106 includes eight terminals thatare shown coupled with eight conductive contacts disposed in a differentone of two different connector assemblies 144.

FIG. 2A is a schematic side view of one embodiment of the two leadbodies 106 shown in FIG. 1 configured and arranged for coupling with thecontrol module 102. A plurality of connector assemblies 144 are disposedin the control module 102. In at least some embodiments, the controlmodule 102 includes two, three, four, or more connector assemblies 144.Typically, the number of connector assemblies 144 disposed in thecontrol module 102 is equal to the number of lead bodies 106 of thelead. For example, in FIG. 2A, the two lead bodies 106 shown in FIG. 1are shown configured and arranged for insertion into two connectorassemblies 144 disposed on the control module 102.

The connector assemblies 144 each include a connector housing 214 and aplurality of connector contacts 316 disposed therein. Typically, theconnector housing 214 defines a port (not shown) that provides access tothe plurality of connector contacts 216. In at least some embodiments,the connector assemblies 144 further include retaining elements 218configured and arranged to fasten the corresponding lead bodies 206 tothe connector assemblies 144 when the lead bodies 106 are inserted intothe connector assemblies 144 to prevent undesired detachment of the leadbodies 106 from the connector assemblies 144. For example, the retainingelements 218 may include apertures through which fasteners (e.g., setscrews, pins, or the like) may be inserted and secured against aninserted lead body (or lead extension).

In FIG. 2A, the plurality of connector assemblies 144 are disposed inthe header 150. In at least some embodiments, the header 150 defines oneor more ports 204 into which a proximal end 206 of the one or more leadbodies 106 with terminals 210 can be inserted, as shown by directionalarrows 212, in order to gain access to the connector contacts 216disposed in the connector assemblies 144.

When the lead bodies 106 are inserted into the ports 204, the connectorcontacts 216 can be aligned with the terminals 210 disposed on the leadbodies 106 to electrically couple the control module 102 to theelectrode contacts (134 of FIG. 1) disposed at a distal end of the leadbodies 106. Examples of connector assemblies in control modules arefound in, for example, U.S. Pat. No. 7,244,150 and U.S. PatentApplication Publication No. 2008/0071320 A1, which are incorporated byreference.

In some instances, the electrical stimulation system may include one ormore lead extensions. FIG. 2B is a schematic side view of one embodimentof a proximal end of a single lead body 106′ configured and arranged tocouple with a lead extension 224 that is coupled with the control module102′. In FIG. 2B, a lead extension connector assembly 222 is disposed ata distal end 226 of the lead extension 224. The lead extension connectorassembly 222 includes a contact housing 228. The contact housing 228defines at least one port 230 into which a proximal end 206 of the leadbody 106′ with terminals 210 can be inserted, as shown by directionalarrow 238. The lead extension connector assembly 222 also includes aplurality of connector contacts 240. When the lead body 106′ is insertedinto the port 230, the connector contacts 240 disposed in the contacthousing 228 can be aligned with the terminals 210 on the lead body 106to electrically couple the lead extension 224 to electrode contacts (notshown) disposed on the lead body 106′.

The proximal end of a lead extension can be similarly configured andarranged as a proximal end of a lead body, such as one of the leadbodies 106, or the lead body 106′. The lead extension 224 may include aplurality of conductive wires (not shown) that electrically couple theconnector contacts 240 to terminals at the proximal end 248 of the leadextension 224. The conductive wires disposed in the lead extension 224can be electrically coupled to a plurality of terminals (not shown)disposed on the proximal end 248 of the lead extension 224.

FIG. 2C is a schematic side view of one embodiment of the lead extension224 configured and arranged for coupling with the control module 102′.The control module 102′ includes a single connector assembly 144.Alternately, the control module 102′ may receive the lead body 106′directly. It will be understood that the control modules 102 and 102′can both receive either lead bodies or lead extensions. It will also beunderstood that the electrical stimulation system 100 can include aplurality of lead extensions 224. For example, each of the lead bodies106 shown in FIGS. 1 and 2A can, alternatively, be coupled to adifferent lead extension 224 which, in turn, are each coupled todifferent ports of a two-port control module, such as the control module102 of FIGS. 1 and 2A.

Degradable binding material can be used to bind together portions of thepaddle body of a paddle lead so that the paddle lead can be implantedpercutaneously (e.g., through a needle, cannula, introducer or thelike.) The paddle body takes on a compacted form when bound. In thecompacted form, the paddle body may be folded, rolled, coiled,compressed, or otherwise deformed from its normal paddle-like form inorder to permit percutaneous implantation. During or soon afterimplantation (for example, within one minute or within five minutes orwithin 10 minutes or within 30 minutes or within 1 hour or within 12hours or within 1 day) the degradable binding material releases thepaddle body allowing it deform into its normal paddle-like form.

FIG. 3A is a cross-sectional view of one embodiment of a portion of apaddle body 400 that has been folded to fit within a bonding material450 that encapsulates the paddle body and fits within a delivery needle460 or the like. The percutaneously implantable paddle body 400 may beformed of a flexible biocompatible, non-conductive material such as, forexample, silicone, polyurethane, combinations thereof, and the like. Thepaddle body 400 includes electrode contacts 410 that will be used forstimulating body tissue.

The percutaneously implantable paddle body 400 is flexible and elasticso that it can be folded, rolled or otherwise compressed into a shapesuitable for implantation via, for example, a percutaneous needle,cannula, or the like (not shown). The percutaneously implantable paddlebody 400 is capable of changing shape after implantation. For example,the paddle body 400 may be formed of, or include, shape memory materials(e.g. nitinol) which can change shape in response to exposure to achange in temperature. Alternatively or additionally, the paddle body400 includes a flexible material that can be rolled, coiled or bent butreturns to a planar or flat surface at body temperature or a flexiblematerial that springs back to a flat, planar shape (or any other desiredpaddle-like shape) when released.

The bonding material 450 can be any suitable biocompatible material thatsufficiently degrades (e.g., dissolves, is bioabsorbed, disperses, orreleases the paddle body) or is otherwise sufficiently removed during,or soon after (for example, within one minute or within five minutes orwithin 10 minutes or within 30 minutes or within 1 hour or within 12hours or within 1 day), implantation to allow deployment of the paddlebody. For example, the bonding material 450 may be a material thatdegrades (e.g., dissolves, is bioabsorbed, disperse, or releases thepaddle body) in the presence of heat or an aqueous environment. As oneexample, the bonding material 450 is a sugar that dissolves in anaqueous environment. As another example, the bonding material 450 can bea material that degrades (e.g., dissolves, is bioabsorbed, disperse, orreleases the paddle body) in the presence of a second agent (e.g.enzyme, solvent, protein, other biomolecule, or the like) which could befound at the implantation site or introduced into the space around thepaddle body via, for example, an injection, the implantation needle orcannula, a fluid channel within the lead, an IV drip, or oraladministration. Examples of suitable bonding materials, include, but arenot limited to, polyglycolic acid (e.g., Biovek™), polylactic acid,polydioxanone, caprolactone, and cyanoacrylate.

In some embodiments, the bonding material 450 fully or partiallyencapsulates encompasses, or encases the paddle body 400 or a portion ofthe paddle body. In other embodiments, the bonding material 450partially surrounds the paddle body 400 so as to maintain the paddlebody as a folded shape during implantation of the paddle body. As anexample, the bonding material may form a shell or cylinder around thepaddle body or a portion of the paddle body or the bonding material mayencapsulate one or more cross-sectional regions of the paddle body. Forexample, the bonding material 450 may be in the shape of rings that aredisposed around the circumference of the paddle body 400. In someembodiments, one, two, three, four or five bonding rings may be disposedaround the circumference of the paddle body 400. It will be understoodthat the shape and size of the bonding material 450 may vary.

After implantation, the bonding material 450 is at least partiallydegraded (e.g., dissolved, bioabsorbed, dispersed, or has released thepaddle body) or is otherwise removed to allow the paddle body 400 todeploy into a paddle shape. FIG. 3B illustrates a portion of the paddlebody 400 of FIG. 3B after implantation and as the bonding material isbeing degraded or otherwise removed. As seen in FIG. 3B, the bondingmaterial 450 is degraded or otherwise removed so that the paddle body400 is no longer constrained within the encapsulating bonding material450. After degradation or removal of the bonding material 450, the bendsof paddle body 400 begin to straighten so that the paddle body 400begins to form a pre-defined planar shape (or another desiredpaddle-like shape).

FIG. 3C illustrates the portion of the paddle body 400 of FIG. 3A afterdeployment. As seen in FIG. 3C, the deployment of paddle body 400 iscomplete, with the paddle body forming a substantially planar surfacesimilar to that of conventional paddle-type leads. After deployment ofthe paddle body 400, the stimulating electrode contacts 410 disposed ona surface of the paddle body 400 are ready for stimulating body tissue.In some embodiments, the deployed paddle body 400 may be rotated orrepositioned after implantation to provide effective therapy.

FIG. 4A is a cross-sectional view of another embodiment of a paddle body500 having fasteners 550 that degrade (e.g., dissolve, are bioabsorbed,disperses, or release the paddle body) or are otherwise removed duringor shortly after implantation to release the paddle body. FIG. 4B is aside view the portion of the paddle body 500 of FIG. 4A. As seen inFIGS. 4A and 4B, the paddle body 500 is wrapped circumferentially withthe electrode contacts 510 on the inside of the wrapped paddle body 500.It will be understood that the paddle body 500 may be wrapped in othershapes before implantation. For example, the paddle body 500 may befolded over, or wrapped around, the longitudinal or lateral centerlinefor implantation. The wrapped shape of the paddle body 500 beforeimplantation is maintained using one or more fasteners 550 disposedalong the length of the paddle body 500. The fastener 550 may be, forexample, a clasp, rivet, tie, pin, or clip useful for coupling twoportions of the paddle body 500. Any number of fasteners may be disposedalong the length of the paddle body 500. In some embodiments, one, two,three, four, five, six, seven, eight, ten, twelve or fourteen fastenersare disposed along the length of the paddle body.

The fasteners are formed of a material that sufficiently degrades (e.g.,dissolves, is bioabsorbed, disperses, or releases the paddle body) or isotherwise sufficiently removed during, or soon after, implantation, toallow deployment of the paddle body. Materials such as those describedabove with respect to the bonding material 450 are generally suitablefor the fasteners. For example, the fasteners 550 may be formed of amaterial that degrades (e.g., dissolves, is bioabsorbed, disperses, orreleases the paddle body) in the presence of heat or an aqueousenvironment. In some embodiments, the fasteners 550 are formed of asugar. In some embodiments, the fasteners 550 are formed of a materialthat degrades (e.g., dissolves, is bioabsorbed, disperses, or releasesthe paddle body) in the presence of a second agent which could beintroduced into the epidural space. In some embodiments, only partiallydegrading or otherwise removing the fasteners during or afterimplantation allows the paddle body to deploy (e.g., unfold.) It will beunderstood that, in some embodiments, remnants of the fasteners mayremain attached to the paddle body for a period of time or evenindefinitely.

FIG. 4C is a cross-sectional view the portion of the paddle body of FIG.4A during deployment. FIG. 4D is a side view the portion of the paddlebody of FIG. 4C during deployment. As seen in FIGS. 4C and 4D, at leastpartial degradation, dissolution, or removal of fasteners 550 initiatesthe beginning of deployment of the paddle body 500. In some embodiments,the paddle body 500 is formed of a shape memory material that reverts toa substantially flat or planar shape after removal of the fasteners 550.

FIG. 4E is a cross-sectional view the portion of the paddle body of FIG.4A after deployment. FIG. 4F is a side view the portion of the paddlebody of FIG. 4A after deployment. As seen in these figures, the deployedpaddle body 500 may be similar in shape and size to conventional paddlebodies, yet is easier and less expensive to implant.

In another embodiment, one or more binding elements may be disengaged ordegraded using electrical current. FIG. 5A is a cross-sectional view ofone embodiment of a portion of a paddle body 600 with one or moreelectrode contacts 610 and one or more current-degradable fasteners 650.As seen in FIG. 5A, the paddle body 600 is wrapped similar to thepercutaneously implanted paddle leads of the previous embodiments. Thesides of the paddle body 600 are held together using one or morecurrent-degradable fasteners 650. The current-degradable fasteners 650may have any suitable shape or size. In some embodiments, thecurrent-degradable fasteners 650 are formed of a material or combinationof materials that degrades, weakens, or melts when at least a thresholdelectrical current is applied. For example, the fastener can be madeusing two different metals where at least one of the metals is thin, hasrelatively high impedance, or has a low melting temperature (or anycombination of these features) such that application of current willdegrade, weaken, or melt the metal or joint between the metals. Asanother example, the fastener may be made of a combination of materialsthat experience electrolytic detachment when current is applied, suchas, for example, platinum and stainless steel or tungsten and stainlesssteel.

The threshold electrical current may depend on the type of material ormaterials used and the physical arrangement of the fastener. With thecurrent-degradable fastener(s) 650 holding the sides of the paddle body600 together, the wrapped paddle body 600 may be percutaneouslyimplanted into body tissue at a suitable position. Current is thenapplied to the fastener(s) 650 so that the fastener(s) break and thesides of the paddle body 600 are released, allowing the paddle body toassume its flat, planar shape (or any other suitable paddle-like shape).

FIG. 5B is a schematic cross-sectional view the portion of the lead ofFIG. 5A during deployment. As seen in FIG. 5B, a current may beintroduced to the current-sensitive binder 650 to break the binder afterimplantation. As seen in FIG. 5B, breaking of the current-sensitivebinder 650 allows the lead 600 to straighten into the eventual shape ofa conventional percutaneous lead 600. FIG. 5C is a schematiccross-sectional view the portion of the lead of FIG. 5A after fulldeployment.

Illustrating an example of a lead with current-degradable fasteners,FIG. 6A is a schematic perspective view of one embodiment of a paddlebody 700 of a lead 705 having current-degradable fasteners 750. As seenin FIG. 6A, the paddle body 700 is in the deployed position and includeselectrode contacts 710 disposed on a face of the lead 700. The paddlebody 700 also includes the remnants of current-degradable fasteners 750on the edges of the paddle body 700. These remnants are provided forillustrative purposes, but it will be understood that, at least in someembodiments, the current-degradable fasteners may be completely removedfrom the paddle body upon deployment.

As seen in FIG. 6A, the percutaneously implantable lead 705 can includedeployment contacts 770 disposed on the lead 705. The deploymentcontacts 770 may be formed of any suitable material including metals,alloys, conductive polymers, conductive carbon, and the like, as well ascombinations thereof. For example, the deployment contacts 770 may bering contacts similar to those used in percutaneous leads.Alternatively, other contact arrangements can be used.

Conductors 760 couple the deployment contacts 770 to thecurrent-degradable fasteners 750. The current degradable fasteners 750can be arranged in parallel, as illustrated in FIG. 6A, or in series orany combination thereof. With the current degradable fasteners 750disengaged, the lead 705 resembles a conventional paddle-type lead.

FIG. 6B illustrates another embodiment in which the lead 700 has only asingle deployment contact 770. The return electrode (not shown) forcurrent flowing through the deployment contact 770, conductor 760, andcurrent-degradable fasteners 750 is remote from the lead 705. Forexample, the return electrode may be provided on the patient's skin orimplanted elsewhere in the patient's body.

FIG. 6C illustrates yet another embodiment in which the electrodecontacts 710 of the paddle body 700 and associated terminals 736 act asthe return electrode(s) for the current-degradable fasteners 750.Alternatively, the terminals 736 and electrode contacts 710 may act asthe active electrode contacts with the conductor 760 and deploymentcontact 770 acting as the return electrode. In yet another embodiment,the current-degradable fasteners 750 may be electrically coupled to atleast two of the electrode contacts 710 of the paddle body 700 so thatflow of current between the electrode contacts causes degradation of thefasteners and deployment of the paddle body.

Some embodiments include structures on the proximal end of the paddlebody that facilitate percutaneous explant of the lead. Such structurescan be incorporated into any paddle body that is capable of folding tofit within a percutaneous explant tool (e.g., a needle) and can be used,if desired, with any of the other embodiments discussed above. FIG. 7Aillustrates a paddle body 800 with electrode contacts 810 and explantstructures 875 disposed at the proximal end of the paddle body 800. Theexplant structure 875 facilitate folding of the lead when encounteringan explant tool 880, as illustrated in FIG. 7B. The explant structureillustrated in FIG. 7A is a tapered end that provides a leading edgewhen the paddle is retracted into a needle. The paddle is formed suchthat this leading edge initiates the “roll-up” of the paddle. Examplesof paddle formations that lend themselves to this “roll-up” include, butare not limited to, a flexible ridge down the center of the paddle, aslightly “C” shaped profile, a very thin paddle, or any combinationthereof. As another example, a draw-string type mechanism could beemployed that allows a user to make adjustments at the proximal end ofthe lead (e.g. the activation of a draw string coupled to the paddle) toinitiate pull back and roll-up of the paddle at the distal end of thelead.

FIG. 8 is a schematic overview of one embodiment of components of anelectrical stimulation system 1000 including an electronic subassembly1010 disposed within a control module. It will be understood that theelectrical stimulation system can include more, fewer, or differentcomponents and can have a variety of different configurations includingthose configurations disclosed in the stimulator references citedherein.

Some of the components (for example, power source 1012, antenna 1018,receiver 1002, and processor 1004) of the electrical stimulation systemcan be positioned on one or more circuit boards or similar carrierswithin a sealed housing of an implantable pulse generator, if desired.Any power source 1012 can be used including, for example, a battery suchas a primary battery or a rechargeable battery. Examples of other powersources include super capacitors, nuclear or atomic batteries,mechanical resonators, infrared collectors, thermally-powered energysources, flexural powered energy sources, bioenergy power sources, fuelcells, bioelectric cells, osmotic pressure pumps, and the like includingthe power sources described in U.S. Pat. No. 7,437,193, incorporatedherein by reference.

As another alternative, power can be supplied by an external powersource through inductive coupling via the optional antenna 1018 or asecondary antenna. The external power source can be in a device that ismounted on the skin of the user or in a unit that is provided near theuser on a permanent or periodic basis.

If the power source 1012 is a rechargeable battery, the battery may berecharged using the optional antenna 1018, if desired. Power can beprovided to the battery for recharging by inductively coupling thebattery through the antenna to a recharging unit 1016 external to theuser. Examples of such arrangements can be found in the referencesidentified above.

In at least one embodiment, electrical current is emitted by theelectrode contacts 134 on the paddle or lead body to stimulate nervefibers, muscle fibers, or other body tissues near the electricalstimulation system. A processor 1004 is generally included to controlthe timing and electrical characteristics of the electrical stimulationsystem. For example, the processor 1004 can, if desired, control one ormore of the timing, frequency, strength, duration, and waveform of thepulses. In addition, the processor 1004 can select which electrodecontacts can be used to provide stimulation, if desired. In someembodiments, the processor 1004 may select which electrode(s) arecathodes and which electrode(s) are anodes. In some embodiments, theprocessor 1004 may be used to identify which electrode contacts providethe most useful stimulation of the desired tissue.

Any processor can be used and can be as simple as an electronic devicethat, for example, produces pulses at a regular interval or theprocessor can be capable of receiving and interpreting instructions froman external programming unit 1008 that, for example, allows modificationof pulse characteristics. In the illustrated embodiment, the processor1004 is coupled to a receiver 1002 which, in turn, is coupled to theoptional antenna 1018. This allows the processor 1004 to receiveinstructions from an external source to, for example, direct the pulsecharacteristics and the selection of electrode contacts, if desired.

In one embodiment, the antenna 1018 is capable of receiving signals(e.g., RF signals) from an external telemetry unit 1006 which isprogrammed by a programming unit 1008. The programming unit 1008 can beexternal to, or part of, the telemetry unit 1006. The telemetry unit1006 can be a device that is worn on the skin of the user or can becarried by the user and can have a form similar to a pager, cellularphone, or remote control, if desired. As another alternative, thetelemetry unit 1006 may not be worn or carried by the user but may onlybe available at a home station or at a clinician's office. Theprogramming unit 1008 can be any unit that can provide information tothe telemetry unit 1006 for transmission to the electrical stimulationsystem 1000. The programming unit 1008 can be part of the telemetry unit1006 or can provide signals or information to the telemetry unit 1006via a wireless or wired connection. One example of a suitableprogramming unit is a computer operated by the user or clinician to sendsignals to the telemetry unit 1006.

The signals sent to the processor 1004 via the antenna 1018 and receiver1002 can be used to modify or otherwise direct the operation of theelectrical stimulation system. For example, the signals may be used tomodify the pulses of the electrical stimulation system such as modifyingone or more of pulse duration, pulse frequency, pulse waveform, andpulse strength. The signals may also direct the electrical stimulationsystem 1000 to cease operation, to start operation, to start chargingthe battery, or to stop charging the battery. In other embodiments, thestimulation system does not include an antenna 1018 or receiver 1002 andthe processor 1004 operates as programmed.

Optionally, the electrical stimulation system 1000 may include atransmitter (not shown) coupled to the processor 1004 and the antenna1018 for transmitting signals back to the telemetry unit 1006 or anotherunit capable of receiving the signals. For example, the electricalstimulation system 1000 may transmit signals indicating whether theelectrical stimulation system 1000 is operating properly or not orindicating when the battery needs to be charged or the level of chargeremaining in the battery. The processor 1004 may also be capable oftransmitting information about the pulse characteristics so that a useror clinician can determine or verify the characteristics.

The above specification, examples and data provide a description of themanufacture and use of the composition of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention also resides in theclaims hereinafter appended.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. A percutaneously implantable paddle lead,comprising: an elongated lead body having a proximal portion and adistal portion; a plurality of terminals disposed on the proximalportion of the lead body; a flexible paddle body coupled to the distalportion of the lead body, wherein the paddle body is compacted into acompacted form that is percutaneously implantable; a plurality ofelectrodes disposed in the paddle body and electrically coupled to theterminals on the proximal portion of the lead body; and a plurality ofcurrent-degradable fasteners in contact with the paddle body and holdingthe paddle body in its compacted form prior to, and during, insertioninto a percutaneous implantation tool, wherein the current-degradablefasteners are configured and arranged to release the paddle body uponapplication of at least a threshold current to allow the paddle body todeploy into its paddle-like form.
 2. The paddle lead of claim 1, whereinthe paddle body is rolled around a longitudinal centerline of the paddlelead.
 3. The paddle lead of claim 1, wherein each of thecurrent-degradable fasteners is at least one clasp, rivet, tie, pin, orclip.
 4. The paddle lead of claim 1, further comprising at least onedeployment contact disposed on the lead body and at least one conductorcoupling the at least one deployment contact to the current-degradablefasteners.
 5. The paddle lead of claim 1, wherein each of thecurrent-degradable fasteners is electrically coupled to at least one ofthe plurality of electrodes.
 6. The paddle lead of claim 1, wherein thepaddle body has a first longitudinal edge and a second longitudinal edgeopposite the first longitudinal edge and the current-degradablefasteners attach the first longitudinal edge to the second longitudinaledge.
 7. The paddle lead of claim 1, wherein the paddle body in thecompacted form is a cylinder.
 8. The paddle lead of claim 7, wherein theelectrodes of the paddle body in the compacted form are disposed on aninterior of the cylinder.
 9. The paddle lead of claim 1, wherein each ofthe current-degradable fasteners comprises a metal having a low meltingtemperature to melt the current-degradable fastener when current isapplied to the current-degradable fastener.
 10. A method ofpercutaneously implanting an implantable paddle lead, the methodcomprising: inserting at least a paddle body of the paddle lead into apercutaneous insertion tool, the paddle body is compacted into acompacted form that is percutaneously implantable, the paddle leadfurther comprising a degradable binding material in contact with thepaddle body and holding the paddle body in its compacted form;implanting the paddle body near tissue to be stimulated in a body of apatient; and degrading the binding material by exposing the bindingmaterial to heat, moisture, or a biomolecule in the body of the patientto release the paddle body from its compacted form and allow it todeploy to its paddle-like form, wherein the exposure causes the bindingmaterial to readily degrade and release the paddle body.
 11. The methodof claim 10, wherein degrading the binding material comprises exposingthe binding material to the heat in the body of the patient, wherein theexposure causes the binding material to readily degrade and release thepaddle body.
 12. The method of claim 10, wherein degrading the bindingmaterial comprises exposing the binding material to the moisture in thebody of the patient, wherein the exposure causes the binding material toreadily degrade and release the paddle body.
 13. The method of claim 10,wherein degrading the binding material comprises exposing the bindingmaterial to the biomolecule in the body of the patient, wherein theexposure causes the binding material to readily degrade and release thepaddle body.
 14. The method of claim 10, wherein the binding materialforms at least one band disposed around a portion of the paddle body.15. The method of claim 10, wherein the binding material forms at leastone fastener.
 16. The method of claim 15, wherein the at least onefastener is at least one clasp, rivet, tie, pin, or clip.
 17. The methodof claim 10, wherein the paddle body in the compacted form is acylinder.
 18. The method of claim 17, wherein the electrodes of thepaddle body in the compacted form are disposed on an interior of thecylinder.
 19. A method of percutaneously implanting an implantablepaddle lead, the method comprising: inserting at least a paddle body ofthe paddle lead into a percutaneous insertion tool, the paddle body iscompacted into a compacted form that is percutaneously implantable, thepaddle lead further comprising a degradable binding material in contactwith the paddle body and holding the paddle body in its compacted form;implanting the paddle body near tissue to be stimulated in a body of apatient; and degrading the binding material by applying at least athreshold current to the binding material causing the binding materialto degrade and release the paddle body from its compacted form and allowit to deploy to its paddle-like form.